Core B was positively reviewed with a priority score in the Outstanding range (146). The Reviewers specifically noted that we had addressed concerns expressed in the previous review, including speech and language capabilities, need for pragmatic language assessment, and concerns about quality control. The review was also positive about the empirical contributions of the Core (see Core B Appendix), which will continue to emerge. The main concern expressed in the most recent review was the amount of data collection that was proposed, involving the Core B assessment as well as the measures associated with Projects 2, 3, and 4. To respond to these concerns, we have added a new section to Core B that provides a flow chart (Figure CB-1, p. 413) illustrating the involvement of a single participant/family. We have also been more specific about the time requirements for each of the projects, including tables CB- 5 (p. 435) and CB- 6 (p. 438). summarizing the time required for the interviews, rating scales, and psychometric assessments. However, please note that we completed Core B (n = 457) and either Project 2 (N-158) with multiple assessments, as well as up to three other projects on approximately 200 participants in the first five years of funding. Participation in these studies required about 4 hours for the Core B psychometric assessment and an hour for the MRI (5 hours), and about 3-4 hours for each of the other three school-age projects. That is a total of about 16 hours if the family and child volunteered for each component, which most who were eligible did. We did not require participation in all 3 components, but most who volunteered did complete all 3 projects. For those who did not continue, they were either not eligible, or found the Core B component all they could handle. In this revision, we have reduced the amount of time for the Core B psychometric assessment (less than 3 hours), and also reduced the time that would be required for Project 3 (2.5 hours for children;3.5 hours for adults). Project 4 is setup to require a 3-4 hour visit, but is divided by a lunch break. It only occurs in Houston, does not involve Project 2 until the end of the 9.5 year follow-up, and can be completed without participants volunteering for all experiments. Therefore, an individual who agrees to participant in Core B, Project 3, and one of the projects for experiment is making a commitment of about 9 hours, a significant reduction from the first 5 years. In addition, Project 3 does not require that the participant attend the Center. It is fully portable. The proposed participant burden is consistent with the commitment that families have made in the past. It is consistent with what we have asked of our participants in other studies. Families are very committed to these research projects. They are aware that this study is one of only a few studies oriented to spina bifida supported by NIH. We also provide benefits in the way of a written report that is highly motivating to parents, consultation about school-related issues and development, a book on education issues for children with spina bifida written specifically for this project, and a clinical interpretation of the MRI, all of which are highly motivating to parents. We provide flexible scheduling and are available on weekends and in the summers. Families are reimbursed for parking, transportation, and time The bottom line is that we were successful in collecting data that placed a greater burden on participants in the in the previous cycle and do not anticipate problems in the next cycle.